Earth Protect Blog

Whats in Your Air Quality Index?

Concerns about air quality are drifting in with the arrival of warm weather.

Monday marked the renewal of what the N.C. Department of Environment and Natural Resources considers “ozone season,” observed through daily air quality forecasts in urban areas.

Officials say it demands more attention in the Charlotte region due to the area’s ongoing struggles to meet federal air quality standards.

“Our region is the only one in the state that currently doesn’t meet federal ozone standards,” said June Blotnick, executive director of Clean Air Carolina, an advocacy group that works with the state to promote good air quality. “From spring to fall, we have levels of high ozone pollution. One of our goals is to make people aware of ozone season and the air quality forecast.”

Air quality has an impact on:

1. Health

Ozone — better known as smog — irritates the linings of our lungs and increases responses to allergens.

When an ozone forecast is orange, red or purple, older people, children with asthma and others with health issues such as heart disease should take heed, Blotnick said.

“Ozone levels are highest between 3 and 7 p.m., so if the forecast is red or orange, you really don’t want to be exercising outdoors during those hours,” she said.

2. The environment

Officials also urge people to adjust their activities on high-ozone days, to keep from adding to the problem.

Though power plants and other industrial operations contribute to the air quality problem, they’ve made good strides to cut back their emissions in recent years, Blotnick said.

Cars and trucks are now the primary culprits.

3. Money

If a region like ours isn’t meeting federal air quality standards, it doesn’t mean industrial growth must come to a halt, said state Division of Air Quality spokesman Tom Mather.

“It might make it tougher to recruit certain types of industries,” he said. “But it’s not like a death sentence for economic growth by any means.”

But new or existing industries that add to the air quality problem may be expected to make up for it in other ways.

“They have to seek offsets, to minimize the overall levels,” Mather said.

“That might mean paying for new emission controls or contributing money to other projects that work to reduce emissions.”

What does the forecast mean?

State and local air quality programs issue forecasts for ozone from April through October. They focus on the pollution likely to be the worst on any given day.

That could be smog.

Or that could be tiny particles in the air — the pollution you’ll hear called “fine particulate matter.”

The Air Quality Index forecasts are color-coded. Green means good air quality, yellow means moderate, orange indicates the air is unhealthy for sensitive groups, and red warns the air is unhealthy for everyone. Purple, the seldom-seen worst categorization, means the air is very unhealthy.

The N.C. Division of Air Quality posts forecasts on its website each afternoon by 3 p.m. and updates them by 10 a.m. the following day, if necessary.

Is air pollution a problem far outside Charlotte?

Not quite. Last year, the state successfully made that case to the Environmental Protection Agency, said Mather.

“We made the argument that portions of outlying counties in the region are pretty rural and were not contributing to the air quality problem,” he said.

Where is air quality monitored locally?

Most of those are in the Charlotte area, and a few other spots in the region.

“We look at where people live and where the industrial sources are, as well as the prevailing winds,” said Mather. “During the ozone season, the winds in Charlotte tend to blow southwest to northeast.”